Map of Blood River

The Crappie: also called papermouth, newlight, strawberry bass or calico bass. But the one thing that you can’t call them is predictable until you understand how they interact with their environment. This proved to be the case at Kentucky Lake during the spring of 2002, despite predictions of an excellent crappie run that year.

Predictions were based on the annual fall trap netting. This type data had been used for the past 18 years on Kentucky and Barkley lakes. This method of sampling yielded data that was believed to be accurate up until about the mid-1990s. This type of data collection helped to support the need for the 10-inch minimum length limit.

Since that time the reservoirs have changed. Creeks have silted in, shoreline habitat has diminished, deep-water habitat has increased (thanks to many dedicated anglers) and water clarity has increased (due to better farming practices and rainfall patterns). Aquatic vegetation came, then went, and is now coming back. Water temperature patterns have changed because of warmer winters and earlier springs. Furthermore, water level fluctuations in the spring have been more prevalent.

Since the mid-1990s, trap-netting data has indicated a change in species composition at Kentucky Lake. Prior to 1997, black crappie collected in trap nets made up only 18 percent of the catch on average. Since that time, black crappie have made up 72 percent of the catch on average.

Why the change? It has been determined in other bodies of water that black crappie prefer clearer water. Black crappie also prefer aquatic vegetation.

So is this change in species dominance real? Although trap netting data suggested a change in species dominance from white to black crappie, the harvest during the 1998 creel survey did not reflect this change. Black crappie made up 12 percent of the crappie caught and 17 percent of the harvest. During the 1991 creel survey, black crappie made up 13 percent of the crappie caught and 16 percent of the harvest.

Although trap nets were catching a higher percentage of black crappie in the late 1990s, anglers were still catching the same percentage of white and black crappie as they did when the trap nets were catching few black crappie.

In 2001, trap nets on the average caught almost five crappie (under 10 inches) per net night. The average for the 18 years of data is closer to two crappie (under 10 inches) per net night. It was speculated from this data that the number of harvestable size crappie in the population was more than double the long-term average. However, the majority of these are black crappie (61 percent).

Assuming that the trap netting data accurately portrays the crappie population in Kentucky Lake, fishing was expected to be twice as good as the average. Therefore, crappie fishing was expected to be excellent for spring 2002. However, crappie anglers will agree that the 2002 spring crappie season was not even half as good as the average.

So what happened? Some believed the fish population was down. Others thought fish populations were not down, but that poor fishing was caused more by muddy water, water level fluctuations and cold fronts.

The 2002 fall trap netting data indicated a catch rate of nearly five harvestable size crappie per net night, similar to the 2001 data. As seen in the past few years, the majority of the catch was black crappie.

Then came the moment of truth: the 2003 spring crappie season. Would anglers harvest support the trap netting data or would it be another poor season? Most anglers reported record catches of crappie this season, with lots of crappie in the 1- to 2-pound range. These crappie did not just grow this big overnight — indicating crappie were there the previous year. If they were there all along in 2002, then why was fishing success so poor that spring?

During this past year — in response to the information that the Department had prior to the 2003 spring season — biologists conducted an intensive crappie research project on Kentucky Lake. This project included radio tracking transmitters implanted inside 30 white and 30 black crappie. These crappie were used to track movement throughout the spawn and into the summer in relation to water changes (temperature, clarity, lake elevation, and flow) and each other (i.e., are the whites doing the same thing as the blacks). These fish were released into the Blood River area of the lake.

The second part of this study involved marking crappie with Floy tags (small plastic yellow tags) to determine exploitation (harvest). These tagged crappie were scattered throughout the Kentucky portion of Kentucky Lake.

As a third part of this study, several anglers were asked to keep an angler diary of their crappie fishing trips. Unfortunately, this portion of the study did not yield enough usable data.

Another part of the study focused on the diet of the crappie. These findings suggest little differences in the diet of the two crappie species.

Biologists also collected data on the crappie population using both electrofishing and trap netting techniques. The spring trap netting yielded a catch rate of harvestable size crappie much less than the previous fall data. However, 75 percent of the crappie netted were blacks. Spring electrofishing suggested a 50-50 ratio of black to white crappie.

Finally, an annual creel survey is being conducted to collect angler data regarding all types of fishing. This portion of the study will help biologists assess the catch and harvest of crappie as well as other sport fish populations.

During the early part of March, 30 white and 30 black crappie were randomly sampled from Blood River with trap nets. There were used for the telemetry portion of this study. Local anglers also donated several crappie and the Department of Fish and Wildlife Resources would like to take this opportunity to again express its gratitude. Within each of the 30 whites and blacks, 15 males and 15 females were targeted in an attempt to understand differences in movement patterns and habitat utilization between sexes.

Most anglers were always very interested in hearing how biologists put the transmitters in the crappie. Crappie collected from nets were placed into a large holding tank that contained aerators and salt. The fish were then hauled back to shore where an operating station was set up.

Next, one fish would be removed from the tank and placed into a 10-gallon tank containing a small amount of anesthetic. Fish would to turn on their sides within 30 seconds. Fish were then removed from the anesthetic and ready for surgery.

Each fish was placed in a device designed to hold it horizontal while lying on its back. For the first half of the surgery, a supply of anesthetic water was flushed over the gills to keep the fish from reviving. Next, a small incision of ½ to ¾ inches was made near the belly region, roughly two scale rows up from the vent.

The radio transmitter was then placed inside of the fish, exposing only the radio antenna. Each transmitter was roughly 24mm long, weighed approximately 3.6 grams, and had a 140- to 280-day battery life. Crappie used in the study weighed an average of 1.13 pounds. As a result, the transmitter accounted for roughly 0.7 percent of the body weight of each crappie. The goal was to stay under 3 percent, to keep the crappie from laboring to maintain themselves in the water column because of the increased body weight from the transmitter.

Once the transmitter had been placed inside the fish, fresh water was flushed over the gills to begin reviving the fish. Between three to five blue, non-dissolving nylon stitches were used to close the incision. A small amount of adhesive was added to each stitch to help maintain the stitch while the wound healed naturally.

Finally, the fish was placed back into the large holding tank and held until it showed signs of complete revival and normal movement, then released. The entire surgical procedure lasted roughly three to four minutes a fish.

Biologists are still analyzing the data collected from the telemetry portion of the study. A more detailed report will be completed this winter. This preliminary summary will only include results regarding trends and biologists’ observations of crappie during the spring and early summer of 2003.

The actual tracking of crappie began around the middle of March. Biologists would have preferred starting to track the fish around the first of March, but bad weather delayed the telemetry project for approximately three weeks.

During the middle and end of March, most of the transmitter crappie were spread out between Fannin’s Point and the mouth of Blood River. Virtually all of the crappie were located along the old river channel that meanders through Blood River. A few fish had already set up on the flats adjacent to the river channel, but the majority of crappie were utilizing the river channel during this time of the year.

Researchers learned that even this early in the season, a large concentration of black crappie had already moved shallow into Jack’s Branch, while most of the white crappie were located toward Sheepridge Point and the mouth of Blood River.

During this time, water temperatures ranged from the mid-50s to the low 60s. Air temperature ranged from the upper 60s during the day to the low 40s in the evenings. Lake elevations remained around winter pool (354.25 – 354.45). No transmitter fish were located in Crappie Hollow during March.

Biologists observed gradual movement of white and black crappie towards the middle and back sections of Blood River during the early part of April. It appears both species utilized the river channel as their means of traveling towards spawning areas. All the transmitter crappie appeared to show a strong preference for areas that possessed a rather large flat with suitable structure, directly adjacent to the old river channel.

However, similar to March, the majority of black crappie were found (on average) to be utilizing shallower water than the white crappie. The black crappie were heavily utilizing the flats around Jacks Branch, Wildcat, and Irvin Cobb. The white crappie were more concentrated on the flats from Fannin’s Point to Sheepridge Point. Several male white and black crappie began to make movements towards spawning areas, indicating the prelude to the spawn. Water temperatures ranged from the upper 50s to the low 60s. Air temperatures ranged from the upper 60s to the mid-50s. The lake elevation began to rise and ranged from 355.5-358.0.

By the middle of April, biologists began to see strong evidence of the spawn as both white and black crappie made strong movements towards flooded buttonball bushes, logs and stake beds. Few of the transmitter crappie were found utilizing the river channel. Again, the black crappies were found to be inhabiting much shallower water than the white crappies. Only black crappie were found in Crappie Hollow, the back of Wildcat, and the back of Irvin Cobb. All of the white crappie were located near the shore from the area around Wildcat to Jacks Branch.

During this time, several of the larger female white crappies never were located in water shallower than 5 feet. One possible explanation for this could be that the larger white crappie spawn deeper than smaller ones. Water temperatures during the middle of April ranged from the mid-60s to the low 70s. Air temperature ranged from the low 50s to the low 80s. The lake elevation ranged from 358.7 to 359.4.

Biologists continued to see signs of spawning through the end of April. Biologists also began seeing white crappie moving into the backs of several of the larger bays, including Crappie Hollow, Wildcat and Irvin Cobb. Both white and black crappie continued to be located near flooded brush and timber in water less than 10 feet deep. However, the general trend of black crappie being found further back in most bays and inhabiting much shallower water continued. Water temperature, air temperature and lake elevation remained similar to the middle of April.

Biologists recorded interesting crappie movement — actually a lack of movement — during early to mid-May. It has always been thought that crappie left the shallows and headed to secondary river channels near drops or ledges to recover from spawning. The study revealed both white and black crappie continued to remain shallow throughout the entire month of May.

One possible explanation was a higher-than-normal lake elevation. Kentucky Lake reached an elevation around 366 (FASL) in May. This high water opened up so much habitat and food to the crappie that there was no need for them to leave the safety of the shallows.

In addition, air temperatures remained cooler than normal. Cooler temperatures pushed water temperatures below 80 during the month. Fish were not pushed to cooler, deeper water. Crappie anglers also experienced a decline in their catch during May. Based on where the telemetry crappie were being found, anglers couldn’t get a boat or a line into some of the habitat that the crappie were in. Some of the crappie being tracked were found in water less than 2 feet deep, next to a flooded fencerow.

From the end of May through June — even into the first few days of July — biologists continued to track many of the radio telemetry crappie in shallow water. The lake elevation had come back down to summer pool, although most of the crappie remained in water under 10 feet deep. Even as water temperature rose into the 80s, many tracked crappie remained shallow.

Many of the larger females migrated to deeper water, but most of the males and several of the smaller females remained shallow. Similar to the preceding months, black crappie were always found further back in the bays and in shallower water than the white crappie. The majority of white crappie were found between Fannin’s Point and Sheepridge Point, while most of the black crappie were located in Crappie Hollow, Jacks Branch and Irvin Cobb.

Water temperatures ranged from the mid-70s to the mid-80s. Air temperature ranged from the upper 70s to the 90s. The lake elevation varied from 359.4 to 359.2.

During the late May and throughout June, anglers enjoyed a plentiful catch of crappie. Numerous anglers reported putting more crappie in their freezers during this period than they did during the spawn. What does this mean? Just because the weather and the water temperature gets hot, that doesn’t mean that crappie fishing is over. Based on the telemetry study, biologists found that anglers could still catch crappie by continuing to fish water shallower than 8 feet during June.

Many of the transmitter batteries began dying by July, which finished this portion of the study. As mentioned earlier, this description of the crappie movement is preliminary. Biologists have yet to fully analyze all the data. Please feel free to contact the Kentucky Department of Fish and Wildlife if you have any questions.

Another question biologists wanted answered was fishing mortality for crappie (also known as harvest or exploitation). One method to measure crappie harvest was to tag a large number of crappie with reward tags. The tags used were yellow Floy tags, which could be returned by anglers for a $5 reward. These anglers were eligible for an additional monetary drawing at the conclusion of the study.

This study would also reveal the true proportion of white and black crappie being harvested. The study began by tagging 1,072 crappie, which consisted of almost equal proportions of white and black crappie. By mid-August, anglers returned approximately 37 percent of the tags.

During the first 10 days of this study, the return rate was just over 7 percent. Approximately 11 percent of the tags were returned within 30 days. These results could be compared to a similar tagging study conducted in 1988. The results from this earlier study indicated fishing mortality was estimated to be at least 45 percent (within one year of tagging 45 percent of the tags were returned). After the first 10 days of this study, approximately 15 percent of the tagged fish had already been caught. Within 30 days of tagging, the return rate was 36 percent.

One explanation for the lower return rate in the current study is potential angler confusion, since there were two tagging projects (Floy and radio) taking place at the same time. Some anglers reported releasing one of the crappie with an implanted transmitter, while actually they released a Floy-tagged crappie. This mistake would result in the underestimation of crappie harvest since the Floy tag was not removed and mailed to biologists.

The Floy tagging study indicated anglers caught an equal number of black and white crappie. Returned tags indicated 47 percent of the harvested crappie were black and 43 percent were white. This does not support the information that had been collected in previous creel surveys.

Previous creel surveys suggested only a small percentage of harvested crappie were black. This inconsistency is possibly an indication that anglers misidentified their catch. This theory is also supported by data that anglers returned with their tags. Of the tags returned, almost 35 percent of the anglers misidentified what species of crappie they pulled the tag from.

Although overall catch rates of the two species were nearly equal, 68 percent of the tags returned during March came from black crappie. White crappie dominated the catch during the other months.

Other information gathered from the Floy tagging study included the type of bait used to catch crappie, habitat where crappie were caught and water depth.

Most crappie anglers used minnows and tube jigs. There was little difference in bait preference for catching either white or black crappie. For both species, tube jigs were used to catch roughly 62 percent of the fish.

The type of habitat from where the tagged crappie were caught varied extremely and has not been completely analyzed.

The depth of where crappie were caught also varied throughout the study. As would be expected, early in March and during June and July, more tagged crappie were caught in water deeper than 5 feet. From mid-March through May, more were caught from water less than 5 feet deep. However, contradictory to the telemetry study, slightly more than half of the Floy-tagged black crappie were caught in water deeper than 5 feet during April and May.

Report prepared by Paul Rister and Ryan Oster, fisheries biologists, Kentucky Department of Fish and Wildlife Resources